This invention relates generally to a polarizable material having a liquid crystal microstructure useful in electrical devices and comprised of one or more amphipathic compounds and a liquid. More specifically, this invention relates to a lamellar liquid crystal material useful in the manufacture of electrical devices such as capacitors, piezoelectric transducers, memory elements, insulators, semiconductors, rectifiers, detectors, electrostatic copying devices and in devices that generate and reflect electromagnetic waves. An embodiment of this invention is a parallel plate capacitor structure that can be charged and discharged comprised of a neat or solid bar phase soap dielectric material positioned between conducting electrodes.
2. Prior Art of the Invention
Various electrical properties of organic materials such as waxes and resins have been disclosed in the prior art. In U.S. Pat. No. 1,952,158 issued to Clark et al. a colloidal gel is disclosed which remains plastic and stable at temperatures as low as -20.degree. C. and as high as 110.degree. C. and which comprises mineral oil and a small proportion of metallic soap as a dielectric material. Clark et al. disclose that when 2 to 12% wt. of metallic soap is added to approximately 90% wt. of mineral oil, a colloidal gel is formed which functions as a dielectric.
U.S. Pat. No. 1,576,096, issued to Davey discloses the use of purified glycerides, essentially water free unsaturated fatty acids or the various soaps of the fatty acids in conjunction with a cellulose paper, as the dielectric material in capacitors. Davey attributes enhancement of the dielectric behavior of the cellulose paper to the addition of the purified glycerides, the essentially water-free unsaturated fatty acids or the various soaps of the fatty acids, which are believed to entrap residual water molecules on the surface of the cellulose paper so that the water does not contribute to the conductivity of the paper.
Methods for producing electrets from molten wax and wax-like materials solidified in an electric field are well known in the art. See U.S. Pat. Nos. 1,804,364; 1,886,235; 2,024,705; 2,986,524; 2,284,039 and 2,460,109. Electrets are quasi-permanent charged dielectric materials useful as tranducers in microphones, earphones, phonograph cartridges and the like.
U.S. Pat. 3,301,786, issued to Klass discloses a synthetic ferroelectric article comprised of a dispersion of a solid silica compound in an organic vehicle such as a polyoxyalkylene, paraffin wax, microcrystalline wax or polypropylene. Klass induces permanent electret properties on the opposite sides of his dispersion by subjecting a melted slab thereof to d.c. current during cooling.
U.S. Pat. 3,458,713, issued to Pearlman et al., discloses an electret comprised of a high molecular weight polycyclic bisphenol polycarbonate which has been permanently electrostatically polarized. Pearlman et al. disclose that such compounds retain electric charge for long periods of time, e.g., ten years.
U.S. Pat. No. 2,916,792, issued to Crook, et al. discloses an apparatus and method for controlling the rate of extrusion of soap bars by passing the soap bars which have a dielectric constant higher than air between the electrodes of a detecting capacitor and measuring changes in the capacitance thereof.
It can be seen from the foregoing prior art references that there is an ongoing effort to fill the need for materials having desirable electrical properties particularly, high dielectric constants and good capacitance and that can be easily and economically produced.